linux-kernel - Re: [PATCH v1] clk: Add devm_clk_{prepare,enable,prepare

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Date:   Mon, 25 Nov 2019 14:16:17 +0100
From:   Marc Gonzalez <marc.w.gonzalez@...e.fr>
To:     Russell King - ARM Linux admin <linux@...linux.org.uk>
Cc:     Stephen Boyd <sboyd@...nel.org>,
        Michael Turquette <mturquette@...libre.com>,
        linux-clk <linux-clk@...r.kernel.org>,
        Linux ARM <linux-arm-kernel@...ts.infradead.org>,
        LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v1] clk: Add devm_clk_{prepare,enable,prepare_enable}

On 25/11/2019 13:52, Russell King - ARM Linux admin wrote:

> On Mon, Nov 25, 2019 at 01:46:51PM +0100, Marc Gonzalez wrote:
> 
>> On 15/07/2019 17:34, Marc Gonzalez wrote:
>>
>>> Provide devm variants for automatic resource release on device removal.
>>> probe() error-handling is simpler, and remove is no longer required.
>>>
>>> Signed-off-by: Marc Gonzalez <marc.w.gonzalez@...e.fr>
>>> ---
>>>  Documentation/driver-model/devres.rst |  3 +++
>>>  drivers/clk/clk.c                     | 24 ++++++++++++++++++++++++
>>>  include/linux/clk.h                   |  8 ++++++++
>>>  3 files changed, 35 insertions(+)
>>>
>>> diff --git a/Documentation/driver-model/devres.rst b/Documentation/driver-model/devres.rst
>>> index 1b6ced8e4294..9357260576ef 100644
>>> --- a/Documentation/driver-model/devres.rst
>>> +++ b/Documentation/driver-model/devres.rst
>>> @@ -253,6 +253,9 @@ CLOCK
>>>    devm_clk_hw_register()
>>>    devm_of_clk_add_hw_provider()
>>>    devm_clk_hw_register_clkdev()
>>> +  devm_clk_prepare()
>>> +  devm_clk_enable()
>>> +  devm_clk_prepare_enable()
>>>  
>>>  DMA
>>>    dmaenginem_async_device_register()
>>> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
>>> index c0990703ce54..5e85548357c0 100644
>>> --- a/drivers/clk/clk.c
>>> +++ b/drivers/clk/clk.c
>>> @@ -914,6 +914,18 @@ int clk_prepare(struct clk *clk)
>>>  }
>>>  EXPORT_SYMBOL_GPL(clk_prepare);
>>>  
>>> +static void unprepare(void *clk)
>>> +{
>>> +	clk_unprepare(clk);
>>> +}
>>> +
>>> +int devm_clk_prepare(struct device *dev, struct clk *clk)
>>> +{
>>> +	int rc = clk_prepare(clk);
>>> +	return rc ? : devm_add_action_or_reset(dev, unprepare, clk);
>>> +}
>>> +EXPORT_SYMBOL_GPL(devm_clk_prepare);
>>> +
>>>  static void clk_core_disable(struct clk_core *core)
>>>  {
>>>  	lockdep_assert_held(&enable_lock);
>>> @@ -1136,6 +1148,18 @@ int clk_enable(struct clk *clk)
>>>  }
>>>  EXPORT_SYMBOL_GPL(clk_enable);
>>>  
>>> +static void disable(void *clk)
>>> +{
>>> +	clk_disable(clk);
>>> +}
>>> +
>>> +int devm_clk_enable(struct device *dev, struct clk *clk)
>>> +{
>>> +	int rc = clk_enable(clk);
>>> +	return rc ? : devm_add_action_or_reset(dev, disable, clk);
>>> +}
>>> +EXPORT_SYMBOL_GPL(devm_clk_enable);
>>> +
>>>  static int clk_core_prepare_enable(struct clk_core *core)
>>>  {
>>>  	int ret;
>>> diff --git a/include/linux/clk.h b/include/linux/clk.h
>>> index 3c096c7a51dc..d09b5207e3f1 100644
>>> --- a/include/linux/clk.h
>>> +++ b/include/linux/clk.h
>>> @@ -895,6 +895,14 @@ static inline void clk_restore_context(void) {}
>>>  
>>>  #endif
>>>  
>>> +int devm_clk_prepare(struct device *dev, struct clk *clk);
>>> +int devm_clk_enable(struct device *dev, struct clk *clk);
>>> +static inline int devm_clk_prepare_enable(struct device *dev, struct clk *clk)
>>> +{
>>> +	int rc = devm_clk_prepare(dev, clk);
>>> +	return rc ? : devm_clk_enable(dev, clk);
>>> +}
>>> +
>>>  /* clk_prepare_enable helps cases using clk_enable in non-atomic context. */
>>>  static inline int clk_prepare_enable(struct clk *clk)
>>>  {
>>
>> Thoughts? Comments?
> 
> These are part of the clk API rather than the CCF API, and belong in
> drivers/clk/clk-devres.c.

I'm totally confused.

Are you saying that a hypothetical devm_clk_prepare() function should not be
implemented in the same file as the "raw" clk_prepare() ?

Regards.